Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves [384]-404. / xiv, 404 l graphs, tables

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves [214]-222. / xii, 222 l maps, graphs, tables

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1969. / Bibliography: leaves [211]-215. / vii, 215 l illus., tables

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Bibliography: leaves 263-269.

Made available in DSpace on 2014-06-11T19:29:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-01Bitstream added on 2014-06-13T20:39:12Z : No. of bitstreams: 1 fernandesjunior_ar_me_ilha.pdf: 353041 bytes, checksum: 24615fb9c4cb2e7357d03d6db98b28cc (MD5) / A interação genótipos com ambientes (GxA) representa uma das principais dificuldades para a seleção nos programas de melhoramento genético de qualquer espécie, seja na fase de seleção ou na recomendação de cultivares, onde os pesquisadores buscam alternativas para minimizar seus efeitos. Entre as alternativas está a escolha de cultivares com ampla adaptação e boa estabilidade. Os resultados de vários ambientes podem ser sintetizados por estudos de adaptabilidade e estabilidade fenotípica, permitindo conhecer melhor a capacidade produtiva e adaptação frente às variações ambientais de novos genótipos. O objetivo deste trabalho foi verificar a adaptabilidade e estabilidade de clones de cana-de- açúcar, além da estabilidade dos ambientes, quanto à produtividade em toneladas de colmos por ha (TCH) e toneladas de pol por ha (TPH) no Estado de São Paulo. Foram avaliados 10 clones e duas testemunhas comerciais de maturação média- tardia em primeira soca em 10 experimentos colhidos em agosto de 2008, utilizando o método de regressão bissegmentada e o método AMMI (Additive Main Effects and Multiplicative Interaction Analysis). A interação GxA para o caráter Pol%cana (PC) não foi significativa e TCH e TPH foram altamente correlacionados (r=0,97), apresentando resultados similares para todas as análises realizadas. Por isso, apenas os resultados de TCH foram apresentados e discutidos. Os resultados dos dois métodos foram comparados e evidenciaram que os clones RB975201, RB975157, RB975932, RB975242 e RB975162 são os mais promissores devido à produtividade acima das testemunhas, a alta estabilidade verificada em um ou nos dois métodos e adaptabilidade ampla ou específica. Os ambientes Tarumã, Guariba e Piracicaba, foram os mais estáveis, podendo servir de referência para recomendações em outras áreas / The genotype x environment interaction (GE) is one of the main difficulties for selection in breeding programs of any species, either at the stage of selection or recommendation of cultivars, where researchers seek alternatives to minimize their effects. Between the alternatives is the choice of cultivars with wide adaptability and good stability. The results of various environments can be synthesized by studies of phenotypic adaptability and stability allowing better understand the production capacity and adaptation to environmental variations ahead of new genotypes. The objective of this study was to verify the adaptability and stability of sugar cane clones, in addition the stability of environments, for productivity in tons of cane per hectare (TCH) and tons pol per hectare (TPH) in São Paulo State, Brazil. Were evaluated 10 clones and two commercial checks of medium-late maturation in first-ratoon of experiments harvested in August 2008, utilizing bissegmented regression method and analysis AMMI (Additive Main Effects and Multiplicative Interaction Analysis). The interaction for the character Pol%cane (PC) was not significant and TCH and TPH were highly correlated (r = 0.97), with similar results for all analyzes. Therefore, only the results of TCH were presented and discussed. The results of two methods were compared and evidenced that clones RB975201, RB975157, RB975932, RB975242 and RB975162 are the most promising due to yield above checks, high stability observed in one or both methods and broad or specific adaptability. The environments Tarumã, Guariba and Piracicaba, are the most stable and may use as reference for recommendations in other areas

Dissertation submitted in the compliance with the requirements for the Masters Degree in Technology: Electronic Engineering, Light Current at Technikon Natal, 2000. / The CANEGRO model is a mechanistic model that describes environmental, physiological and managerial features of the agricultural sugarcane production system. The model originated from many sources of crop, climatic and soil research work. This caused a fragmentation in the model's components. The objectives of this study was to give a detailed model overview after an investigation into the model's code, published and unpublished documentation and to propose a mechanistic approach in the modelling of tiller populations. / M

No description available.

Sugar production in Natal agricultural estates and industrial mills began in the 1800's. The Canestone Sugar Mill and Estates (now 145 years old) which is the focus of this study, is still in operation although renovations and improvements have been done over the years. Initially the owners of these sugar farms in the Natal area employed Black labourers but soon realized that this method of cheap and available labour was not entirely suitable for their needs. In the late 1850's they initiated a process of change which saw the first group of Indian nationals arrive in South Africa in 1860. This group of people came specifically to work on these sugar farms; and their descendants, some now in their 5th generation, are still employed by the Canestone Sugar Company. With time, the standards of living have altered and the conditions of work have transformed. Thus, the level of communication has been modified and possibly improved. So the assumption can be made that there has been an element of change in existence. The following is an account of how the lives of the Canestone Sugar workers have been modified over the years with specific changes that took place from the 1960s to 1998. This thesis considers the world of Canestone from the 1960's to 1998, an area where sugar manufacturing in the North coast of Natal was extremely successful. The main intention of the work is to explain how a majority workforce of illiterate people was monopolised by a handful of literate people who used literacy and the art of writing to subjugate thousands of people into accepting, non-questioning beings. Account is taken of orality and general primary oral practices that were entertained by management whenever necessary. This thesis breaks new ground as the first detailed account of the challenges of change in a new-found democracy, described in an agrarian and industrial context. It also attempts to identify the way in which managerial changes in corporate environments can take place. In this dissertation I have compiled the many stories of the workers of the Canestone Sugar Company into one story. Against a backdrop of South African history of colonialism, apartheid and its new-found democracy, the Canestone Sugar Company reflects vestiges of the old era. In attitude, perception, and behaviour there are indications of this in the company; interviewees stated that "this is a white man's paradise "where "the black man had to pay for his head" and where many felt that the company "drank their blood, left them with their bones" and where they worked "worse than animals" until "their sweat turned into blood". I shall investigate the present status of the individuals of this multicultural working community. The individuals that I interviewed share a common work culture and they experience a subservient position as a result of the power dynamics that are in place. Van den Berghe looked at Canestone with an unbiased opinion and results of his work are the starting point of my discussion. His proposals, made in the early sixties, have not reached fruition as a great sense of dissonance still exists between the workforce and the management. This dissertation looks at how the Company has changed, and what role communication has played in the process. / Thesis (Ph.D.)-University of Natal, Durban,2002.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Wetlands are key to providing important ecosystem goods and services yet they are under threat from a number of anthropogenic activities. In particular, in this study area, agriculture in the form of sugarcane farming is a threat to wetlands as sugarcane is reliant on a good water supply. The impacts of sugarcane farming emanates from the fact that sugarcane is a mono crop that requires wetland resources and uses a lot of pesticides and fertilisers. Despite the assumed contribution of sugarcane farming to wetland loss and degradation, few studies have quantitatively assessed the spatio-temporal changes in wetland extent as well as changes in water quality because of this activity. This study assesses the impacts of sugarcane farming on wetland extent and water quality in two coastal wetlands of KwaDukuza, North coast of Zululand, South Africa. Specifically this study sought to (i) assess the impacts of sugarcane farming on the spatial extent of wetlands between 1959 and 2012, (ii) determine if sugarcane farming negatively affect water quality within the wetlands and (iii) evaluate the perceptions of local farmers regarding impacts of sugarcane farming on wetlands. Results of the study indicated an increase in the extent of Zinkwazi sugarcane fields from 62.3% to 67% between 1959 and 1989 and Nonoti sugarcane fields’ extent increased from 50.5 % to 56.4% between 1959 and 2000. The last decade from the year 2000 showed gradual decrease in the area of wetland farmed by sugarcane due to the global sugar price remaining static while the cost of farming inputs increased and due to conversion of some farms to urban developments. Unfortunately, this has not lead to an increase in wetland area as the waterfront type developments, as well as a formal settlement have replace the sugarcane in the wetlands. Water was analysed for nitrogen (N), phosphorus (P) and potassium (K) and results for both Zinkwazi and Nonoti indicated an increasing trend of N and P from upstream to the middle region of the rivers and a decreasing trend of the N and P from the middle region to downstream. Sugarcane farming does not take place below the middle region and so does not provide fresh sources of these nutrients. The downstream area where the N and P decrease also coincides with the area of the river under tidal influence such that the N and P are being diluted by the incoming tidal seawater. K showed an increasing trend from upstream to downstream and its values were higher than N and P. Concentrations of N and P above the South African water quality guidelines for aquatic ecosystem were recorded in the middle region. Furthermore, farmers’ perceived wetlands to have been transformed to agricultural land and related these changes to their sugarcane farming activities. It can thus, be concluded that sugarcane farming has resulted in wetland loss as well as deterioration of water quality within the Zinkwazi and Nonoti wetlands in KwaDukuza. In that regard, there isneed to engage farmers in wetland management programs in order to reduce the negative environmental impacts associated with sugarcane farming in wetlands. / AFRIKAANSE OPSOMMING: Vleilande is die sleutel tot die verskaffing van ‘n belangrike ekosisteem dienste, maar hulle is onder ‘n bedreiging deur 'n aantal menslike aktiwiteite. In besonder in hierdie studie area, is Argriculture in die vorm van suikerriet boerdery is bedraging vir vleilande, en suikerriet is afhanklik van 'n goeie watervoorraad. Ten spyte van die veronderstelde bydraes van suikerriet boerdery, is die vleiland aan die agteruitgang, 'n Paar studies het kwantitatief die tydruimtelike veranderinge in die vleiland, sowel as veranderinge in die gehalte van water as gevolg van hierdie aktiwiteit waargeneem. Spesifiek is hierdie studie gepoog om (i) te bepaal wat die impak van suikerriet boerdery op die ruimtelike omvang van die vleiland tussen 1959 en 2012 is, (ii) bepaal of suikerriet boerdery negatief beïnvloed is deur die gehalte van water in die vleilande en (iii) die persepsies van plaaslike boere rakende die evalueering en impak van suikerriet boerdery op die vleilande. Resultate van die studie het aangedui 'n toename in die omvang van Zinkwazi suikerriet velde van 62,3% tot 67% tussen 1959 en 1989, en die Nonoti suikerriet velde toegeneem het met 50,5% tot 56,4% tussen 1959 en 2000. Die laaste dekade van die jaar 2000 het geleidelike afname in die area van die vleilande getoon, omdat suikerriet as gevolg van die globale suiker prys die koste van boerdery-insette verhoog het, en dit het gelei tot die omskakeling van 'n paar plase na stedelike ontwikkelings. Ongelukkig het dit nie gelei tot 'n toename in die vleiland gebiede nie, met die gevolg die waterfront tipe ontwikkelings, asook 'n formele nedersetting, vervang die suikerriet in die vleilande. Water is ontleed vir N, P en K en resultate vir beide Zinkwazi en Nonoti, het aangedui 'n toenemende tendens van stikstof en Fosfor. Dit gaan stroomop na die middel-streek van die riviere en 'n dalende neiging van die N en P uit die middel streek stroomaf. Suikerriet boerdery vind nie plaas onder die middel streek nie, en so is daar nie vars bronne, wat van hierdie voedingstowwe verskaf nie. Die stroomaf gebied waar die N en P ‘n afname het, val ook saam met die gebied van die rivier onder die gety , en dit beinvloed sodanig dat die N en P se water verdun word deur die inkomende gety se seewater. K het 'n toenemende neiging van stroomop en stroomaf en sy waardes is hoër as van die N en P. Konsentrasies van N en P bo die Suid-Afrikaanse water standaard riglyne is in die middel streek aangeteken. Verder, beskou boere dat die vleilande behoort te verander om die landbougrond en verwante veranderinge aan hul suikerriet boerdery en aktiwiteite. Ons kan dus aflei dat suikerriet boerdery het gelei tot die vleiland se verlies asook die verandering in die watergehalte in die Zinkwazi en die Nonoti vleilande in KwaDukuza. In dié verband is dit nodig dat die boere in die vleiland by programme betrek word ten einde die negatiewe omgewingsimpakte wat met suikerriet boerdery gepaard gaan in vleilande te verminder.

The South African (SA) sugar industry supports approximately 50,940 small and large scale producers who collectively produce 22 million tons of sugarcane seasonally, on average. SA farmers face many challenges that lead to an uncertain decision making environment. Despite a general consensus among agricultural economists that risk constitutes a prevalent feature of the production and marketing environment, various authors have recently stated that risk-related research has failed to provide a convincing argument that risk matters in farmers' decisions. The various shortcomings of previous research have been identified and recommendations for the future proposed. Recommendations include that the focus of future risk research should be on holistic risk management. This study firstly identified the perceived importance of 14 separate sources of risk for a sample of 76 large-scale commercial sugarcane farmers in KwaZulu-Natal. Once a sufficient understanding of the risk perceptions of respondents had been attained, their use of 12 risk-related management strategies was determined. Principal components analysis (PCA) was used to investigate how individual management instruments are grouped together by respondents into choice brackets in order to make use of complementary and substitution effects. The study then proposed and demonstrated a technique that may be used in future research to isolate the effects of risk on individual risk-related management responses by modelling the management strategies contained within individual choice brackets with two-stage least squares regression analysis (2SLS). The most important risk sources were found to be the threats posed by land reform, minimum wage legislation and the variability of the sugar price, in that order. PCA identified seven risk dimensions, collectively explaining 78% of the variance in all 14 risk sources considered. These dimensions were: the "Crop Gross Income Index", "Macroeconomic and Political Index", "Legislation Index", "Labour and Inputs Index", "Human Capital and Credit Access Index", "Management Index" and the "Water Rights Index". Respondents were also asked questions regarding risk-related management strategies, including diversification of on-farm enterprises, investments and management time. PCA identified six management response brackets, collectively explaining 77% of the variance in the 12 responses considered. These response indexes were: the "Mechanisation and Management Bracket", "Enterprise and Time Diversification Bracket", "Insurance and Credit Reserve Bracket", "Geographic and Investment Diversification Bracket", "Land Trade Bracket" and the "Labour Bracket". Lastly, the study proposed a methodology for investigating the role of individuals' risk preferences in decision making. The recommended technique involves the simultaneous modelling of the major risk-related management strategies within each management response bracket, using 2SLS. A measure of risk preference was included in the 2SLS analysis to establish the influence of risk on decision making. By applying this methodology to the data obtained in this study, respondents were shown to be taking advantage of various complementary and substitution effects that exist between management responses. This was evident from the PCA and confirmed for the first previously identified management response bracket using 2SLS regression analysis. Risk attitude was shown to be a significant determinant of management decisions regarding the extent to which back-up management is kept in reserve. Important policy recommendations stemming from this study include that government review restrictive labour legislation and decrease the uncertainty surrounding new land redistribution legislation. Farmers need to make better use of available information by considering the effects of any single management decision on separate decisions, enabling them to take further advantage of substitution and complementary effects that may exist between management strategies previously considered in separate decision brackets. The fact that mechanisation and labour use occur in separate risk-related management response brackets in this study is an example of one such substitution effect that farmers do not seem to be utilising in terms of their management decision making. Future research using time series data is important in order to identify how risk perceptions and management portfolios change over time. Also, further research using the methodology proposed in this study may prove to be a useful means of more adequately addressing the question "Does risk matter in farmers' decisions?" / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.